Not as bad as the ones in Milan as they don't play chicken with your head. However, the things won't move even if you're inches away from them.
...buy some pigeon feed from this vendor. Soon you'll have pigeons eating from your hands, your mouth, and your ears.
St. Mark's Square is full of pigeons. I mean they are EVERYWHERE! If you are not careful, you will end up with pigeon poop on your head. We almost did!
Yes, it is true, the pigeons are all over Piazza San Marco! Look at this cute little kid! Reminds me of Tralfager Square in London or even NYC!